RU2549367C1 - Mass spectrometer - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: device relates to the field of measurement equipment, in particular, to mass spectrum analyser, and may be used to study substance structure, surface of solid bodies and processes of interaction as particles collide in gases and plasma. The technical result is higher accuracy of measurement of mass composition of ion flux and lower distortion in measurements due to elimination of edge effects present in usage of permanent magnets. In the device there is an analyser, which serves as a separator of arriving particles of the ion flux by speeds and comprises two cylindrical electrodes placed coaxially, with an electromagnetic winding that covers them, which provides a combination of electric and magnetic fields with orthogonal orientation of their intensities. Further in the mass spectrometer there is an electrostatic analyser along with direction of ion flux propagation, and such analyser separates the flow of particles arriving into it with the same speed according to the value of energy ratio to the charge and serves as a separator by masses. Besides, the device is equipped with generators of voltage pulses of complex shape to control voltage of outer and inner cylindrical electrodes, and also to control electromagnetic winding of the separator by speeds and electrodes of the separator by masses.

EFFECT: capability is implemented to perform measurements of ion propagation functions with high resolving capacity by speeds for each determined mass, which provides for high accuracy of measurement of ion flux mass composition.

6 dwg

Description

The proposed device relates to the field of measurement technology and, in particular, to mass spectrum analyzers.

The main fields of application for energy and mass analyzer of charged particles are: the study of the surface of solids, the study of the structure of matter and interaction processes in collisions of particles in gases and plasma.

When creating mass spectrometers, the aim is to create devices that allow the study of ionized particles included in plasma streams and ion beams with high accuracy. As is known, to obtain a mass spectrum, particles must be ionized, i.e. pass through the ionization chamber, then they are pulled out of it by an extractor, fall into the separator, are divided by mass in it and enter the collector, creating a current in its circuit. To obtain the spectrum of the ionic component, given the large energy spread of the ions, an analyzer with a combination of electric and magnetic fields is used.

Thus, a mass spectrometer with a particle analyzer with crossed electric and magnetic fields is known (FR 2695756 A1, IPC H01J 49/48, published 03/18/1994) - [1], in which the ion analyzer is at least one cylindrical electrode to create an electric field region, an electromagnet to create a magnetic field perpendicular to said electric field, and reversal lenses to direct particles into a subsequent cylindrical electrode. This device allows you to increase the resolution by lengthening the area of the analyzer with crossed fields.

The disadvantage of this device is the complexity of the design and assembly of the device to ensure high accuracy studies. Reversal lenses inevitably cause scattering of particles, which leads to a decrease in current at the output of the analyzer, and, consequently, to a decrease in the resolution of the device.

The closest in technical essence to the proposed device is a mass spectrometer (US 4054796 A, IPC H01J 49/28, published 10/18/1977) - [2], which contains an ionization chamber, a diaphragm, a particle analyzer, which is a parallel electrode for creating between them an electric field and magnetic pole pieces, to create a magnetic field oriented perpendicular to the specified electric field, a diaphragm, an electrostatic particle separator, providing correction of the energy dispersion, the diaphragm mu and collector.

The disadvantage of this device is the use of magnetic pole pieces, since the permanent magnets have a nonuniform magnetic field propagating from the center to their edges, which, as a result, leads to aberrations. In addition, the use of permanent magnets does not provide the ability to change the magnitude of the magnetic induction in the gap between them, which limits the use of the device.

The basis of the proposed technical solution is the task of creating a mass spectrometer with a high resolution, which minimizes the distortions in measurements arising from the edge effects that are present when using permanent magnets and studies the ion velocity distribution function for different masses.

The technical effect of this invention is:

- improving the accuracy of measuring the mass composition of the ion flux, i.e. device resolution;

- the possibility of obtaining a distribution function for a specific ion mass over velocities;

- expanding the functionality of the device due to the possibility of obtaining the spectrum of the ion flux by changing the magnetic or electric fields.

The solution of the problem and the corresponding technical result are achieved by the fact that in the mass spectrometer containing sequentially placed in a grounded vacuum chamber in the direction of propagation of the studied ion flow from its inlet, the separator according to ion velocities, which is made in the form of two electrodes parallel to each other with current leads and has grounded input and output diaphragms, an ion mass separator made in the form of an electrostatic analyzer, which has two parallel d it has a cylindrical electrode with current leads and is equipped with a grounded input and output diaphragms with current leads, as well as a collector with a current lead and a recording device attached to it outside the vacuum chamber, while the separator electrodes are made in the form of coaxial external and internal cylindrical electrodes, between which thin dielectric rings are placed at the ends, and a through hole is made in each ring in its longitudinal direction, the axis of the through holes in the separation rings The pores in terms of ion velocities coincide with the axes of the inlet of the vacuum chamber Z, as well as the holes of the inlet and outlet diaphragms of the separator in terms of ion velocities, while the separator in terms of ion velocities is equipped with an electromagnetic coil, which has a current lead and encompasses the outer and inner cylindrical electrodes of the separator in terms of ion velocities with the outer and inner sides, respectively, as well as the rings between them, and the input diaphragm of the separator according to the ion velocities is placed in the vacuum chamber at its inlet, in addition The property is equipped with complex voltage pulse generators for controlling the voltage of the external and internal cylindrical electrodes, as well as for controlling the electromagnetic coil of the separator according to ion velocities, and the voltage on the separator electrodes by ion masses, the current leads of which are connected to the outputs of the corresponding voltage pulse generators of complex shape, in addition , the device is equipped with a multi-channel pulse generator, which has independent channels in the number of voltage pulse generators of the layer hydrochloric shape and is configured to generate voltage pulses on independent channel outputs, which are connected to the inputs of the pulse complex shape voltage generator to control the voltages on the electrodes a separator of the masses of the ions with a time delay t _ass a time span distances ions between the outlet orifice of the separator for the ion velocity and the input diaphragm of the separator according to the masses of ions relative to the voltage pulses at the outputs of independent channels that are connected to the inputs of the pulse generators complex voltages for controlling the voltage of the external and internal cylindrical electrodes, as well as for controlling the electromagnetic winding of the separator according to ion velocities.

The analyzer proposed in this device with a combination of electric and magnetic fields is made with the orthogonal orientation of the electric and magnetic fields and plays the role of a separator according to the velocities of the particles of the ion flow entering it. In this mass spectrometer, after the speed separator, there is an electrostatic analyzer that separates the particle flux by the magnitude of the energy to charge ratio. Since, at a fixed speed, the particle energy is proportional to the mass, then the ions will be divided by mass at the output of the electrostatic analyzer. Thus, in the proposed device, it is possible to measure the distribution function of ions by velocity for different masses. This circumstance expands the capabilities of the mass spectrometer, provides a distinctive approach to the diagnosis of charged particles and high accuracy of studies of the composition of ionized substances.

Figure 1 - schematically shows the proposed mass spectrometer in section.

Figure 2 - schematically shows the electrodes of the separator according to the speeds of the ions, insulated by rings of dielectric and equipped with an electromagnetic winding.

Figure 3 shows the diagrams of pulsed voltages from the outputs of the independent channels of a multichannel pulsed generator for triggering complex voltage pulse generators (a variant of controlling a mass spectrometer with a constant voltage on an electromagnetic coil).

Figure 4 - shows the diagrams of changes in the values of electric potentials on the electrodes of the separators according to the velocities and masses of ions and their differences from time to time;

Figure 5 shows the diagrams of pulsed voltages from the outputs of the independent channels of a multi-channel pulsed generator for triggering complex voltage pulse generators (an option for controlling a mass spectrometer with a pulsed signal on an electromagnetic coil).

Figure 6 shows the diagrams of changes in the values of electric potentials on the electromagnetic coil of the separator in terms of speed, on the electrodes of the separator in mass and their difference in time.

The device of FIG. 1 comprises successively placed in a grounded vacuum chamber - 1 in the direction of propagation of the test ion flow from the inlet (with the Z axis) of the vacuum chamber 1, ion separators in speed and mass.

The separator for ion velocities in figure 1 and figure 2 contains: an external cylindrical electrode - 2 with a current lead; inner cylindrical electrode - 3 with current lead; input diaphragm - 4, which is grounded; output diaphragm - 5, which is grounded. The external 2 and internal 3 electrodes are made coaxial with the axis O.

The separator by mass of ions in figure 1 has: an electrode - 6 of a cylindrical shape with a radius of R6; electrode - 7 cylindrical with a radius of R7; input diaphragm - 8, which is grounded; output diaphragm - 9, which is grounded.

In the vacuum chamber 1 in the direction of propagation of the ion flux after the separator by mass, a collector - 10 is placed.

In addition, the separator according to ion velocities has: a thin ring - 11 made of a dielectric, located at the end of the electrodes 2 and 3 in the inlet along the ion flow direction; a thin ring - 12 of a dielectric, placed in the outlet end in the direction of propagation of the ion flow by the end of the electrodes 2 and 3.

In this case, the rings 11 and 12 have through holes made in the longitudinal direction, respectively 13 and 14, the axes of which coincide with the Z axis of the inlet of the vacuum chamber 1 and the axes of the inlet 4 and outlet 5 of the separator diaphragms according to ion velocities.

In addition, the speed separator is equipped with an electromagnetic coil - 15, which has a current lead and covers the outer electrode 2 from its outer side, and the inner electrode 3 from its inner side, and the rings 11, 12 located at their ends.

Outside the vacuum chamber 1, the proposed mass spectrometer contains: a complex voltage pulse generator - 16 for controlling the voltage at the external 2 electrode of the separator according to ion velocities; complex voltage pulse generator - 17 for controlling the voltage on the inner 3 electrode of the separator according to ion velocities; complex voltage pulse generator - 18 for controlling the voltage of the electromagnetic winding 15 of the separator by speed; a complex shape voltage pulse generator - 19 for controlling the voltage at the electrode 6 of the separator by ion masses; complex voltage pulse generator - 20 for controlling the voltage at the electrode 7 of the separator by ion masses; multichannel pulse generator - 21 with the number of independent channels not less than the number of pulse generators of complex voltage in the device as a whole.

In addition, to the current lead of the collector 10 outside the vacuum chamber 1 is attached a recording device - 22.

The mass spectrometer shown in FIG. 1 and FIG. 2 operates as follows.

In the speed separator (Figure 2), the outer 2 and inner 3 cylindrical electrodes of length l _c , with radii R _c2 and R _c3, respectively, with a common axis O are made of metal (or of a metal mesh), while satisfying the condition (R _c2 -R _c3 ) << R _c2 and are located coaxially and are fixed to each other by means of thin dielectric rings 11 and 12.

A toroidal electromagnetic coil 15 with a uniform number of turns in azimuth is wound along the outer surface of the electrode 2 and the inner surface of the electrode 3. A direct current is passed through the electromagnetic winding 15, and a constant magnetic field of the azimuthal direction is generated by the induction value B in the gap between the electrodes 2 and 3.

A negative voltage is supplied to the internal electrode 3, and positive to the ground (the mass spectrometer case) to the external electrode 2. Thus, between the two electrodes 2 and 3, when voltage is applied to them and current is passed through the electromagnetic coil 15, crossed electric and magnetic fields arise. The ion velocity separator has a structure that provides a magnetic field uniformly distributed along the surfaces of the outer 2 and inner 3 electrodes. As a consequence of this, a decrease in edge effects and a reduction in aberrations. An input diaphragm 4 is located at the particle inlet of the speed separator, an output diaphragm 5 is located at the particle exit, the diameter of the apertures 4 and 5 is much smaller than the difference of the radii R _c2 and R _{c3 of the} outer 2 and inner 3 electrodes, respectively. The thin dielectric rings 11 and 12 have holes, the diameter of which is also much smaller than the difference of the radii R _c2 and R _c3 , and the axes are located strictly along the axis of the inlet Z of the vacuum chamber 1 along the generatrix of the cylinder with radius R _cZ and axis O (see Fig. 2 ) Thus, particles can pass through the input 4 and output 5 of the diaphragm along crossed electric and magnetic fields. The electrodes 6 and 7 of the electrostatic analyzer are two cylindrical electrodes located coaxially at a distance of (R ₇ -R ₆ ) << R ₇ from each other. A positive voltage is supplied to the electrode 7, and a negative voltage relative to the earth (vacuum housing 1) is supplied to the electrode 6. An electrostatic analyzer (ion mass separator) rotates particles 90 ° (either 180 ° or 270 °).

Multi-channel pulse generator 21 is used to synchronize the start of pulse voltage generators of complex shape 16, 17, 19, 20. The plot of the voltage pulses generated by the generator 21, used to start the pulse voltage generators of complex shape 16, 17, 19, 20, are presented in Figure 3.

The pulse voltage generator 16 supplies a signal to the external electrode 2 of the speed separator. The pulse voltage generator of complex shape 17 provides a signal to the inner electrode 3 of the speed separator. The pulse voltage generator of complex shape 19 provides a signal to the electrode 6 of the separator by mass. The pulse voltage generator of complex shape 20 provides a signal to the electrode 7 of the separator by mass. The pulse repetition period T of pulse voltage generators of complex shape 16, 17, 19, 20 is the same and should be significantly longer than the flight time t of the _flight of the ion beam particles along the Z axis in the speed separator equal to:

where: l _c is the length of the speed separator;

υ _min is the lowest particle velocity in the beam.

When voltage is applied by a multi-channel pulse generator 21 to pulse voltage generators of complex shape 16, 17, 19, 20, time delays of pulses are provided (see FIG. 3). First, the pulses are supplied by pulsed voltage generators of complex shape 16 and 17 to the outer 2 and inner 3 electrodes, respectively, after a time t _ass (t _ass is the delay time of the pulse supply between pulsed voltage generators of complex shape 16, 17 and 19, 20, which should be greater the time of flight of the ions, the distance between the output diaphragm 5 of the speed separator and the input diaphragm 8 of the electrostatic analyzer - mass separator) pulses are supplied by pulsed voltage generators of complex shape 19 and 20 to the electrodes 6 and 7, respectively naturally.

, спустя интервал времени, равный T, сигнал изменится до величины

, и так далее до

(см. фиг.4). Генератор импульсных напряжений сложной формы 17 воспроизводит сигналы ступенчатой формы, полярность которых противоположна, а длительность совпадает с сигналами, вырабатываемыми генератором импульсных напряжений сложной формы 16. Величина начального потенциала от генератора импульсных напряжений сложной формы 17 -

, спустя интервал времени, равный T, сигнал изменится до величины

, и так далее до

. Разность потенциалов между внешним 2 и внутренним 3 электродами изначально равна

, спустя интервал времени, равный T, разность потенциалов между внешним 2 и внутренним 3 электродами

, и так далее. Таким образом,

,

, …,

, где n - количество шагов, определяющих точность измерения распределения ионов по скоростям.The pulse voltage generator of complex shape 16 reproduces a step-shaped signal. The amplitudes of the potentials applied to the external electrode 2 increase with time. The value of the initial potential from the pulse generator of complex shape 16 -

, after a time interval equal to T, the signal will change to a value

and so on until

(see figure 4). The pulse voltage generator of complex shape 17 reproduces step-shaped signals whose polarity is opposite, and the duration coincides with the signals generated by the pulse voltage generator of complex shape 16. The initial potential from the pulse voltage generator of complex shape 17 -

, after a time interval equal to T, the signal will change to a value

and so on until

. The potential difference between the external 2 and internal 3 electrodes is initially equal to

, after a time interval equal to T, the potential difference between the external 2 and internal 3 electrodes

, and so on. In this way,

,

, ...,

, where n is the number of steps determining the accuracy of measuring the distribution of ions over velocities.

The pulse voltage generator of complex shape 19 reproduces a sawtooth waveform with an amplitude of the potential applied to the electrode 6 and decreasing to a value of F ₆ . The complex voltage pulse generator 20 reproduces a sawtooth waveform of a potential applied to the electrode 7 and increasing to a value of Ф _{7 of} opposite polarity with the amplitude of the potential applied to the mass spectrometer electrode 6. The potential distribution between the electrodes 6 and 7 has a sawtooth shape and increases to a value equal to U _7-6 , which is determined by the potential difference applied to the electrodes 7 and 6, U _7-6 = Ф ₇ -Ф ₆ .

In this case, from a voltage pulse generator of complex shape 18, a constant voltage is applied to the electromagnetic winding 15 (see FIG. 3).

Mass spectrometer works as follows.

заряженных частиц направлена перпендикулярно взаимно ортогональным векторам напряженности электрического

поля и индукции магнитного

поля. На частицу, движущуюся в скрещенных электрическом и магнитном полях, действуют электрическая сила

, равная

(где q - заряд иона), и магнитная сила Лоренца

(см. Фиг.2). Электрическая сила

направлена от внешнего электрода 2 к внутреннему электроду 3, как показано на Фиг.2, магнитная сила Лоренца

направлена от внутреннего электрода 3 к внешнему электроду 2, так как в выражении

присутствует векторное произведение скорости частицы и индукции магнитного поля, следовательно, результирующий вектор, то есть сила Лоренца, направлен взаимно ортогонально двум указанным векторам. При условии, когда

, эти силы точно уравновешивают друг друга. Если это условие выполняется, частица будет двигаться равномерно и прямолинейно. При заданных значениях электрического и магнитного полей сепаратор скоростей выделит частицы, движущиеся с определенной скоростью

, независимо от величины их массы. Для частиц с иной скоростью сепаратор скоростей является ионной ловушкой.The studied ion flow passes through a grounded inlet diaphragm 4, then enters the speed separator. The speed separator acts on charged particles (ions) like a Wien filter, the physical principle of which is as follows: initial velocity

charged particles directed perpendicular to mutually orthogonal electric intensity vectors

field and magnetic induction

fields. A particle moving in crossed electric and magnetic fields is affected by an electric force.

equal to

(where q is the ion charge), and the magnetic Lorentz force

(see Figure 2). Electric power

directed from the outer electrode 2 to the inner electrode 3, as shown in FIG. 2, the Lorentz magnetic force

directed from the inner electrode 3 to the outer electrode 2, as in the expression

there is a vector product of particle velocity and magnetic field induction, therefore, the resulting vector, that is, the Lorentz force, is mutually orthogonal to the two indicated vectors. Provided when

, these forces precisely balance each other. If this condition is satisfied, the particle will move uniformly and rectilinearly. For given values of electric and magnetic fields, the speed separator will isolate particles moving with a certain speed

, regardless of the size of their mass. For particles with a different velocity, the velocity separator is an ion trap.

влетающих в него ионов параллельно направлению оси Z, а напряженность электрического поля перпендикулярна направлению скорости ионов в направлении от внешнего электрода 2 к внутреннему 3, индукция магнитного поля ортогональна направлению скорости ионов и напряженности электрического поля.In the proposed speed separator, the direction of speed

ions entering it parallel to the direction of the Z axis, and the electric field is perpendicular to the direction of ion velocity in the direction from the outer electrode 2 to the inner 3, the magnetic field is orthogonal to the direction of ion velocity and electric field strength.

и индукция магнитного поля

распределены по одинаковому закону. Учитывая расчеты в работе [3], можно утверждать, что в предлагаемой конструкции сепаратора скоростей обеспечивается условие, когда E(r)~1/r и B(r)~1/r (где: r - расстояние, которое пролетает ион вдоль оси Z при заданных значениях E и B), а это способствует отсутствию искажений и высокой точности прибора.In the work (“Peculiarities of the motion of charged particles in translationally symmetric mutually orthogonal electric and magnetic fields”, P. M. Tyuryukanov // Journal of Technical Physics, Volume LI // 1981) - [3] describes in detail the conditions for the motion of charged particles in translational symmetric electromagnetic fields. Calculations are given for the longitudinal and transverse components of the ion velocities in crossed fields. And also an expression is obtained for the boundary of the region possible for particle motion. From the above calculations, the conditions for the motion of ions in crossed fields are visible. The distribution of the electrostatic potential in the space between electrodes 2 and 3 has a logarithmic dependence. The calculations presented in [3] show the importance of the fact that the electric field

and magnetic field induction

distributed according to the same law. Given the calculations in [3], it can be argued that in the proposed design of the speed separator the condition is provided when E (r) ~ 1 / r and B (r) ~ 1 / r (where: r is the distance that the ion flies along the axis Z at given values of E and B), and this contributes to the absence of distortion and high accuracy of the device.

на участке длительностью T₁ и величиной разности потенциалов

. После увеличения потенциала до величины

, в течение времени T₂ сепаратор по скоростям выделяет из ионного пучка частицы со скоростью

. Аналогично при возрастании потенциала до

в течение времени T_n сепаратор скоростей выделит частицы со скоростью

.Since stepwise signals of different polarity are supplied to pulse voltage generators of complex shape 16 and 17, and a constant voltage is applied to the electromagnetic coil 15 from the voltage pulse generator of complex shape 18, the speed separator emits particles with a certain speed

on the site of duration T ₁ and the value of the potential difference

. After increasing the potential to a value

, over time T _{2 the} speed separator separates particles from the ion beam at a speed

. Similarly, when the potential increases to

over time T _{n, the} speed separator will emit particles at a speed

.

Then particles with the same speed value, passing through the grounded output diaphragm 5 of the separator in terms of speed, and then diaphragm 8, fall into the mass separator field (electrostatic analyzer) between the electrodes 6 and 7.

The movement of the ion in the gap between the electrodes 6 and 7 occurs in a circle, the radius of the trajectory R ₀ which is determined by the expression:

where: m is the mass of the ion;

υ is the ion velocity;

q is the ion charge;

U is the magnitude of the electric field voltage between the electrodes 6 and 7 of the separator by mass.

Consequently, ions passing through the velocity separator have a fixed velocity υ and various masses m. At a given voltage U in the separator, the masses will move along the trajectories corresponding to their masses. Thus, at a certain value of voltage U, particles with a certain mass m will be selected. By setting various values of the voltage U, it is possible to obtain the entire mass spectrum at a fixed speed υ.

, выделенные сепаратором скоростей в течение времени T₁ при величине потенциала

(см. Фиг.4), попадая в поле сепаратора по массам электродов 6 и 7, благодаря сигналу пилообразной формы на них, сепарируются по массам. Поскольку при фиксированной скорости энергия частицы пропорциональна массе, то на выходе сепаратора по массам ионы будут разделены в соответствии с их массовыми числами. В течение второго интервала времени T₂ частицы со скоростью

, прошедшие сепаратор скоростей, когда напряжение между его электродами принимает величину

, также сепарируются по массам, попадая в поле сепаратора по массам между электродами 6 и 7. Аналогично в последующие интервалы времени Т₃, Т₄ … T_n при величинах напряжений на сепараторе скоростей

,

…

, сепаратором по скоростям будут выделяться частицы с фиксированными скоростями

,

, …

, а затем сепарироваться по массам в поле сепаратора по массам.The supply of sawtooth signals from pulse generators of complex shape 19 and 20 to the electrodes 6 and 7 provides a scan of the mass spectrometer. The amplitude of the potential difference U _7-6 = Ф ₇ -Ф ₆ is selected depending on what is the mass of the heaviest particle in the spectrum. Particles with speed

separated by a speed separator over time T ₁ at the potential value

(see Figure 4), getting into the field of the separator by the masses of the electrodes 6 and 7, due to the sawtooth signal on them, are separated by masses. Since at a fixed speed the particle energy is proportional to the mass, then at the separator output, the masses of the ions will be separated in accordance with their mass numbers. During the second time interval T ₂ particles with speed

passing the speed separator when the voltage between its electrodes takes the value

are also separated by mass, getting into the separator field by mass between the electrodes 6 and 7. Similarly, in subsequent time intervals T ₃ , T ₄ ... T _n at the voltage separator

,

...

, with a speed separator, particles with fixed speeds will be released

,

, ...

and then separated by mass in the mass separator field.

Then, the ions separated by masses pass through the grounded diaphragm 9 and fall on the collector 10, creating a current in its circuit, which is recorded by the device 22 in the form of a series of peaks.

на участке длительностью T₁ и величиной создаваемой магнитной индукции В₁. Затем сигнал на электромагнитной обмотке 15 увеличивают и создают индукцию магнитного поля величиной В₂, при этом в течение времени Т₂ сепаратор частиц выделяет из ионного пучка частицы со скоростью

. Аналогично при возрастании индукции магнитного поля до B_n сепаратор скоростей выделит частицы со скоростью

. Временная задержка t_зад импульсов на электромагнитную обмотку 15, электрод 6 и электрод 7 показаны на Фиг.5.Also, the speed spectrum scan can be obtained by changing the magnetic field of the electromagnetic winding 15 (see Figure 5), which extends the functionality of the mass spectrometer. In this case, the electric field between the electrodes 2 and 3 must be constant, which is ensured by applying to the electrodes 2 and 3 from pulse generators of complex shape 16 and 17 potentials of a constant value, thus, the electric field in the gap between the external electrode 2 and the internal electrode 3 is constant . From the voltage pulse generator of complex shape 18, a stepwise signal is supplied to the electromagnetic coil 15 (see Fig. 6), the speed separator emits particles with a certain speed

on the site of duration T ₁ and the magnitude of the created magnetic induction In ₁ . Then the signal on the electromagnetic winding 15 is increased and magnetic field induction of a value of B _{2 is created} , while during the time T _{2 the} particle separator releases particles from the ion beam at a speed

. Similarly, with increasing magnetic field induction to B _{n, the} speed separator will separate particles with a speed

. The time delay t _back pulses to the electromagnetic coil 15, the electrode 6 and electrode 7 are shown in Fig.5.

Further, the principle of operation of the mass spectrometer is similar to the previously described embodiment of the device.

для каждой определенной массы m_n.Using the proposed design of the mass spectrometer will allow you to implement the task of obtaining the distribution of ions of the analyte in speeds

for each specific mass m _n .

Claims (1)

A mass spectrometer containing a separator arranged in series in a grounded vacuum chamber in the direction of propagation of the studied ion flow Z from its inlet by ion velocities, which is made in the form of two electrodes parallel to each other with current leads and has a grounded input and output diaphragms, a separator by mass of ions made in the form of an electrostatic analyzer, which has two cylindrical electrodes parallel to each other with current leads and is equipped with grounded input and output diaphragms with current leads, as well as a collector with a current lead and a recording device connected to it outside the vacuum chamber, characterized in that the separator electrodes in speeds are made in the form of external and internal cylindrical electrodes coaxial to each other, between which thin dielectric rings are placed at the ends, a through hole is made in each ring in its longitudinal direction, and the axis of the holes in the separator rings coincide in speed with the axes of the inlet of the vacuum chamber Z, and also the openings of the inlet and outlet diaphragms of the separator in terms of speed, while the separator in terms of speed is equipped with an electromagnetic winding that has a current lead and covers the outer and inner cylindrical electrodes of the separator in terms of speed from the outer and inner sides, respectively, as well as the rings between them, and the inlet diaphragm of the separator in speeds are placed in a vacuum chamber at its inlet, in addition, the device is equipped with complex voltage pulse generators to control the voltage of the external and internal cylindrical electrodes, as well as for controlling the electromagnetic winding of the separator by speed and the separator electrodes by mass, the current leads of which are connected to the outputs of the corresponding voltage pulse generators of complex shape, in addition, the device is equipped with a multi-channel pulse generator, which has independent channels in the number of voltage pulse generators of complex forms and is configured to generate voltage pulses at the outputs of independent channels that are connected to the inputs complex voltage pulse generators for controlling the mass separator electrodes with a time delay t _ass more than the ion travel time between the separator output diaphragm in speed and the mass separator input diaphragm relative to voltage pulses at the outputs of independent channels that are connected to the inputs of complex voltage pulse generators for controlling the external and internal cylindrical electrodes, as well as the electromagnetic winding of the separator in terms of speed.

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